1. Field of the Invention
This invention relates to an apparatus such as a camera or the like adapted for use with a film cartridge and more particularly to a device for loading or unloading the film cartridge on or from the apparatus.
2. Description of the Related Art
A known film cartridge is called "a thrust type cartridge film" and arranged to have the leader part of a film completely stowed within the cartridge together with the film and to send out the leader part of the film by means of a film feeding fork of a camera. The camera can be easily loaded with the film cartridge of this type in a manner called "drop-in loading", as the film cartridge can be put into a film loading chamber of the camera from the axial direction of the cartridge.
A feature of this film cartridge lies in that the film stowed in the cartridge is provided with a magnetic recording part.
The conventional drop-in loading type camera which uses the film cartridge of this kind requires an operator to open the lid of a cartridge chamber of the camera by hand, to axially insert the film cartridge into the cartridge chamber deep enough to have it hit the bottom of the cartridge chamber and then to close the lid of the cartridge chamber by hand. The lid opening-and-closing operation on the cartridge chamber has been troublesome. Besides, if the lid of the cartridge chamber is closed before the film cartridge is correctly inserted deep enough, the cartridge would interfere with the lid of the cartridge chamber to prevent the latter to be smoothly closed and thus to necessitate the operator to do the inserting operation over again. The camera thus has had a drawback in its poor operability.
To eliminate this drawback, the applicant of the present application has proposed a camera arranged to carry out the cartridge loading operation by means of an electric motor. According to this, the film cartridge is pulled into the camera and moved out of the camera by pushing rollers against the shell of the film cartridge while the rollers are driven to rotate by the motor. This camera, however, has presented the following problem.
Generally the cartridge shell varies in size within the range of tolerance. To accept all cartridge shells of such different sizes, the cartridge chamber is arranged to be somewhat larger than a standard size. The cartridge shell and a film winding spool shaft which is disposed within the cartridge are also arranged to have some play between them to absorb the tolerances assigned to them.
Therefore, in transmitting the driving force of the film feeding fork disposed on the side of the camera to the spool shaft disposed within the cartridge with the fork allowed to engage the spool shaft, the arrangement to restrict the position of the cartridge shell by applying a pressing load of the rollers to the cartridge shell for loading the camera with results in the film cartridge, the film winding spool shaft within the cartridge not smoothly engaging the fork of the camera. The load on the fork then fluctuates to cause changes in the speed at which the fork sends out or rewinds the film. If information is read out or written into the magnetic recording part of the film under such a condition, not only would the information reading or writing result in some errors but also the load on a film feeding (thrust) driving action would become too heavy for a normal film feeding or transportation.